Electric fuse.



L. B. BUCHANAN.

ELECTRIC FUSE.

111111.1@1111011 1111.11 Nov. 27. 1914. 11E11EWE111.1AR.21,19111.

1,281,285. y v A Patente 00h15, 1918-.,

UNITED sTATEs PATENT oEEicE.

LEONARD B. BUCHANAN, OF WOBURN, MASSACHUSETTS.

ELECTRIC FUSE.

Specification of Letters '.Patent.

Patented oet. 15, 191s.

Applcaton'led November 27, 1914, Serial No. 874,147. Renewed March 21, 1918. Serial No. 223,869.

To all Iwlw/1t t may concern:

Be it known that I, LEoNARn B. BU- GHANAN, a citizen. of the United. States, residing at liVoburn, in the county of Middle- SeX and State of Massachusetts, have invented an Improvement in Electric Fuses, of whiclrthe following' is a specification. i

This invention relates to t'uses and particularly to an indicator device adapted to show conspicuously and indicate'rom casual inspection whether the fuse is `in operative condition or blown out. In devices of this character heretofore produced, it has been customarywto provide an lindicator' member visible at the outside of the fuse-holder andhaving controlling-means connected to the fuseelement at an intern'xediate portion thereof formed to localize the burning' outl action, in a manner so that when the fuse burns out at this point, said visible indicator member is caused to be acted on by a spring or like means to push it out of a holder or otherwise change its position or appearance.

This-connection ot' said indicator member or its controlling-means to the fuse-strip is, however, objectionable in certain particulars such as interfering with the convenient rcnewal of the fuse-strip aftery burning out and because it is otherwise desirable that the fuse-strip be clear of hitch-ups with` extraneous elements through its operative portion. The prime object of the present invention is, therefore, to provide an indicator-device 4for-a fuse having' means for conspicuously changing its position or appearance and with its indicator-wire extending into the localized blow-out Zone of the fusestrip but free and clear of' connection or engagement therewith adapted to be acted on when the fuse blows out, so as to permit the indicatoredeviee to operate. In accordance with my invention, the indicator-device is preferably formed as a self-contained entity adapted to be applied bodily to the fuse holder and to be located in proper proximity tothe blow-out Zone of the fuse-strip without actually contacting with the use-strip.

The foregoing, and other objects and features of the invention will be better under- `stood from the following detailed descripwith the accompanyvindicator-device detached, and in position ready to be operated.

Fig. 3 is a. similar detail showingthe indicator-device after a blow-out has taken placefand,

Fig. 4 is an elevation of another form of indicator-device embodying this invention.

The fuseholder l0 may be of the usual cylindrical type formed of insulatingmaterial havingT metallic end-caps 11,12. The fuse-strip 13 extends between these end-caps, and at its central portion it is or may be reduced in cross-section, as at let, to define the point at which the fuse will burn out and to constitute a localized blow-out Zone. The fuse-strip may be supported by detachable mounts, such as are commonly employed in fuses having removable fuse-strips, or it .may be supported by permanent mounts as is also now common. ln the holder, toward one end thereof, l arrange the indicator-den vice of the present invention. The indicator-device, here shown, comprises afsupport, an indicatormcmber arranged on said support, actuating-means for said member also arranged on said support, an indicator-wire attached at one end tosaid member, and a bracket arranged on thesupport to which the other end of said wire is attached, said bracket being arranged to hold the endsportion of the indicator-wire in the blow-out zoneot' 'the usestrip. The support of the indicator-device may be arranged for perma` nent or detachable connection with the holder, and both forms of support are here shown. In Figs. l to 3, a support :tor permain the .holder 10, and having a Hanged head at its inner end, and having its outer end turned over upon the outside of the holder. In Fig. 4 a detachable form of support is shown, comprising a collar 25, with a {iangcd head at its inner end, and several bendable prongs Q6, at its outer end, adapted to be bent over upon the outside of the holder. So far as my invention is concerned, the support, however, may be otherwise'.constructed, yet 'having' the same ca abilities. Adjacent the flangedhead of the collar, a bracket or arm ltd/is arranged, which extends in toward the eentenof the tuse'anrl is bent down to a point adjacent the reduced portion 14 of the fuse-strip, where it is formed with a hook 17, although said bracket may be otherwise arranged on said support. F or connecting the bracket with the support it may have an aperture to embrace the collar and for security, said aperture may be of a size to snugly t the collar. Fitted to the outside of the collar is a plate 18, which may be in the shape of a vdisk and colored so as to be conspicuously discernible, said disk serves as the indicator-member. A coil spring 19, which serves as the actuating-means for the disk-member, is housed in the collar and rests on the head thereof, having its outer end enga-ged with the disk-member. The disk-mein er and the spring engaged 'therewith are normally drawn down so that the disk-member rests on the top of the collar and the spring is under compression, by a ine flexiblel indicator-wire 20, which leads down through the collar and has its end soldered or otherwise suitably secured to the hook 17 of the bracket. The inner end-portion of the indicator-wire 2O is held by the bracket adjacent to, though wholly out of contact with the central-portion 14 of the fuse-strip. It will be observed that the indicator-device thus described constitutes a self-contained entity, the indicator-wire 20, holding the indicator-member normally down onto the top of its support, so that when its support is arranged inthe holder,

said indicator-member will occupy a position substantially Hush with the outer surface of the holder without in any Wise interfering with the' fuse-strip or requiring any fitting thereto, and so that the fuse-strip may be :in-

serted or renewed independently of the indicater-device. The indicator-device and the fuse-strip, though, coperating in'use towindicate the blow-out of the fuse, are practically independent elements, adapted to be separately assembled with the fuse-holder.

' The essential feature of course, isthe cooperative assemblage of elements, so that the inner end-portion of the indicator-wire will be supported close enough to the blow-out or arc-forming zone tobe acted on suiiciently to rupture or release said wire upon the blowing out of the fuse. It is an advantage to enable the indicator-device to be mounted and held separate from and free of the fuse-strip, and I desire to protect this feature irrespective of structural details,

hence the present embodiment is to be considered as illustrative and not restrictive.

Having described my invention, what I claim as new and desire to secure by Let- `ters Patent is l. An electric fuse, comprising a fusestrip, a holder therefor, and an indicatordevice supported wholly by said holder, said indicator-device consisting in an indicatormember, ay spring for changing the position of said indicator-member, an a'rni extending into the blow-out-zone, but free of said fuse strip, and a flexible member for holding said spring normally inactive and connected to said arm in the blow out zone of the fusestrip, for the purpose sta-ted.

2. An indicator-device for electric` fuses made as a self-contained entity comprising a support arranged for detachable connection with the holder, an indicator-member and actuating means engaging said member and arranged on said support, a bracket also arranged on said support andan indicatorl wire connected with the indicator-member at one end and with the bracket at the other-` engaging said member and arranged on said'V collar, a bracket also arranged on said collar` and an indicator-wire connected with the indicator-member atone end and with the bracket at the other end, andadapted to be held by said bracket in the blow-out zone of the fuse-strip with the actuating-means in readiness to act upon the blowing of the fuse, substantially as described.

In testimony whereof, Ihave signedI my nameto this specification, in the presence of two subscribing ,witnesses- LEONARD B. BUCHANAN.

Witnesses: A

B.' J. Noms,

H. B. Davrs. 

